1. Field of the Invention
The present invention generally relates to tape transport apparatus and, more particularly, is directed to an endless tape transport apparatus, such as an announce machine, a commercial signal transmitting apparatus, a master tape transport apparatus of an audio tape and video tape dubbing apparatus and so on for repeatedly transporting a magnetic tape on which a predetermined signal is recorded beforehand.
2. Description of the Prior Art
FIG. 1 shows a previously-proposed endless tape transport apparatus, such as an announce machine, a commercial signal transmitting apparatus and so on for repeatedly transporting an endless magnetic tape on which a predetermined signal is recorded beforehand.
The endless tape transport apparatus shown in FIG. 1 is what might be called a loop bin type. As shown in FIG. 1, this endless tape transport apparatus is comprised of a tape compartment 1 called a loop bin in which a tape or endless tape 2 is housed and a tape transport compartment 3 in which the endless tape 2 supplied from the tape compartment 1 is transported. The tape transport compartment 3 includes therein one tape feeding mechanism 4 formed of a capstan 4a and a pinch roller 4b to take out the endless tape 2 from the tape compartment 1 through a tape exit 1a at a predetermined speed and another tape feeding mechanism 5 formed of a capstan 5a and a pinch roller 5b to transport the endless tape 2 at a predetermined speed so as to feed the endless tape 2 into the tape compartment 1 through a tape entrance 1b. A cue signal detecting head 6, a reproducing head 7 and a recording head 8 are all provided between one tape feeding mechanism 4 and the other tape feeding mechanism 5. The cue signal detecting head 6 is adapted to detect the cue signal inserted into the endless tape 2 so as to detect the starting point, the tape end and so on of the information signal recorded on the endless tape 2. The reproducing head 7 is adapted to reproduce the information signal recorded on the endless tape 2 and the recording head 8 is adapted to record the reproduced number of this endless tape 2 on a predetermined position of the endless tape 2. The reproducing head 7 is adapted to reproduce the information signal recorded on the endless tape 2 and the recording head 8 is adapted to record the reproduced number of the endless tape 2 on a predetermined position of the endless tape 2. In that event, one and the other tape feeding mechanism 4 and 5 constitute a closed loop to thereby perform satisfactory reproduction and recording. In FIG. 1, reference numerals 9a, 9b, 9c and 9d respectively designate tape guides which guide the endless tape 2.
A tape stripping guide 10 is provided between the capstan 5a of the other tape feeding mechanism 5 and the tape entrance 1b of the tape compartment 1 in order to strip the endless tape 2 stuck to the capstan 5a. A tape wrapping preventing guide 11 is provided between the pinch roller 5b of the other tape feeding mechanism 5 and the tape entrance 1b in order to prevent the endless tape 2 from being wrapped around the pinch roller 5b.
An impedance roller 22 enables the tape feeding mechanism 4 to stably transport the endless tape 2 so that the endless tape 2 can be prevented from being transported recklessly. This impedance roller 22 generates a constant back tension for the endless tape 2.
According to the above endless tape transport apparatus shown in FIG. 1, when the tape feeding mechanisms 4 and 5 are driven, the endless tape 2 is transported around the tape transport compartment 3 and the tape compartment 1 in a loop fashion, whereby the information signal recorded on the endless tape 2 can be reproduced repeatedly.
In the conventional endless tape transport apparatus as described above, if the endless tape 2 is released from being held between the capstans 4a, 5a and the pinch rollers 4b, 5b of the tape feeding mechanisms 4, 5 such as when the transport of the endless tape 2 is stopped and the power switch of the apparatus is turned off, then the endless tape 2 falls from and is disengaged from the capstans 4a, 5a and the pinch rollers 4b, 5b. As a consequence, when the transport of the endless tape 2 is started again, the endless tape 2 must be set again. If the endless tape 2 is continuously held between the capstans 4a, 5a and the pinch rollers 4b, 5b for a long period of time after the transport of the endless tape 2 is stopped, there is then the risk that the pinch rollers 4b, 5b will be deformed because the pinch rollers 4b, 5b are made of resilient material. Furthermore, if the endless tape 2 is continuously held between the capstans 4a, 5a and the pinch rollers 4b, 5b for a long period of time, then the endless tape 2 also will be deformed and damaged.